After pelleting at a pilot scale, the pelleted feed contained
potential probiotic lactobacilli at a concentration of 10.8 ±
0.02–9.8 ± 0.022 log CFU kg−1. Most post-weaning pig diets
are made up of feed in amounts which vary from 1 to 2 kg
per pig [30]. In practice, dosed pigs received ca. 9–10 log CFU
of probiotics daily or every few days [39]. Almost all strains
selected in this study could be used as additives in pelleted
feed. This study showed that pelleted feed containing L. plantarum
4.1 and L. reuteri 3S7 inhibited the growth and survival
of pathogenic E. coli ED36 and PWD5 strains under simulated
gastrointestinal conditions.
The complexity of the intestine may lead to variations between
animals; therefore, probiotic strains may have differing
effects upon individual animals. This is a good reason for using
mixtures of strains [20]. This study identified a rather large
number of isolates from pig feces and selected some probiotic
candidates to be used in pelleted feed. In particular, L. reuteri
3S7, and L. plantarum 4.1 are: (i) naturally present at elevated
concentrations in the GIT of pigs; (ii) resistant to feed pelleting
(ca. 10 log CFU kg−1); (iii) resistant in vitro to gastric and
intestine fluids; and (iv) inhibitory, with a complementary spectrum,
toward potential pathogen bacteria.